sharpening angles

[Keith Sinclair]

At the end of the day Im not to upset about it since this is a learning experience. Next time with my Shun Im going to go the micro bevel route since that should give me a more stable edge.

Sounds like a good plan.Trouble with Damascus blades & low shallow angles,even the stone mud can scuff up the sides of the blade.Yes you can sand out the scratches on the damascus,but the trick is not to put them there in the first place.

I like low starting angles on Gyuto's,then raise the spine & blend in a second higher bevel,when you do this you can hear the final bevel being cut in on the stone.A steady consistant spine is more important then % of angle.

On my work knives never used a Damascus blade.Start wt. shallow bevel close to the stone,then kick in final bevel.Did not care what the sides of the blade looked like as long as it was sharp & cut well.

These days sharpen Shuns alot for other people.Still start wt. shallow angle,don't let hardly any mud build up on the stone(rinse it off)Inspect your edge,even at the shallow angle should not hit the damascus line,just a little polish above the edge.It is a good idea to establish a higher final bevel as well on the Shun,it is still very sharp,good cutting edge & not as fragile.

 

[Eric]

Just find the right angle for the primary angle by feel and sound. Use the sharpie if you can't find the bevel. Trust yourself, and listen to he sound as you gently push your blade. The slightly high pitch, different feel and confirmation with sharpi will tell you. Don't be afraid you'll only learn by doing, seeing what works and what doesn't. The height varies depending on the width of the blade, basic trig. ER

 

[jer]

Different stones will give different feedback so it may be more difficult to feel when you are hitting the edge with some stones compared to others. If you want to try to match the existing bevel, try moving the blade in an edge leading motion on a wooden cutting board, piece of paper, etc. This will allow you to feel when the edge begins to catch, which will give you an idea of the approximate angle at what you will hit the edge during sharpening and the corresponding height of the spine.

 

[stevenn21]

how do i polish scratches out of a Damascus?

 

[ThEoRy]

You have to scratch up the surface on both sides of the blade with automotive sandpaper with a grit lower than the scratch you created then progress up to the finish you would like. Or you could simply buff the blade on both sides, etch it, then buff it again. Either way it's an arduous task.

 

[hobbitling]

Would that remove the damascus pattern, and if so, would it have to be re-etched?

 

[stevenn21]

Would that remove the damascus pattern, and if so, would it have to be re-etched?

i dont think it would remove the pattern thats where the steel has been folded its not just been etched on

 

[split0101]

I think what you end up losing the contrast between layers but the layers are still there. However I'm only aware of damascus clad knives so I don't know how thick that layer is over the core steel. I'm not sure if you kept going with buffing that you would hit the core metal.

 

[hobbitling]

I understand that I wouldn't remove the layers of steel (unless I drastically thinned the blade down to the core steel) My understanding was that polished damascus has very little contrast between the layers of steel. The contrast is achieved by either etching with acid, or sometimes by bead blasting, which changes the texture or color of one type of steel more than the other.

 

[Justin0505]

All of you forgot to account for the temperatures (ambient, steel, abrasive, and water), altitude, barometric pressure, and moon phase when writing your sharpening formulas.
For shame.


As for refinishing the damascus once you're all done with the maths and experimentation:
http://www.kitchenknifeforums.com/showthread.php/6474-Damascus-Knives-amp-Re-Etchng

 

[Geo87]

Would that remove the damascus pattern, and if so, would it have to be re-etched?

I've recently removed a lot of scratches on a friends shun, sanding with wet & dry. It did not remove the Damascus

 

[Geo87]

I guess I wanted to go with something more than trial and error. For example during my last sharpening session I decided to go about 10-12* on my shun. I was able to pop hairs and shred magazine paper with little effort. After about an hour of prep work on a poly board the edge was in horrible shape. It rolled on me, started to chip and overall looked like it was in a fight.

Next time I will need to go back to 16-20* since that seems to hold up better. I don't know if that is because its a shun or if that's because VG10 should not be pushed that steep.

At the same time I put the same angle on my Carter but it held up much better. I still need to put it through a proper prep session on that poly board. If it does hold up dthen I'll continue sharpening it at that angle.

Next up is 51200, I'm going to go steep and see how it holds up. I have a feeling I might need to keep it in the mid-teens. Suggestions?

I don't think it's a vg10 thing, more a shun thing. I used to have a shun and a few work colleagues have them, keeping it at 16 seems the best bet, with good thinning behind the edge. Although also had em at 10 degrees and it held a lot longer than you described... On poly boards. Maybe focus your efforts on the final stages on sharpening.

I agree with everyone that said maths to determine angles is pretty unnecessary although I can see how it would appeal to some. A rough estimate with some paper plane folding skills will do the trick many other things are more important than calculating angles to perfection ... Just my 2 cents

 

[Geo87]

Here's a photo, the shun on the right is one year old, quite a few scratches from diamond steel abuse

Shun on the left is 7 years old , sanded with wet and dry 400, 800, 1200 then metal polish .

 

[Keith Sinclair]

AS mentioned auto wet dry paper.Start with finer grit see if it takes out the scratch,if not go to a lower until find grit that removes them,inspect the blade make sure they are all gone.Then go to finer grits to finish.It's not that much work as long as the scratches are lite surface ones.Be aware that you are working with a sharp edge edge,I like to wear leather gloves while doing this kind of work.